When a camera shake acts on a lens, a camera shake reducing unit that is mounted on a lens driver with camera shake reducing function will cause the auto-focusing unit to swing in a direction that is at right angle to the optical axis of the lens, so as to avoid blurring of image that is imaged on the image sensor. For example to take patent document 1 as representative, a lens driver with camera shake reducing function primarily comprises: an auto-focusing unit that moves the lens along the optical axis direction; a suspension wire suspension support that extends along the optical axis direction; and a camera shake reducing unit that causes the auto-focusing unit to swing in a direction at right angle to the optical axis direction.
FIG. 7(a) is an overall perspective view of a lens driver 30 with camera shake reducing function, and FIG. 7(b) is an exploded perspective view of the lens driver with camera shake reducing function. The optical axis of the lens 33 is set to Z (Z-axis) direction and two directions perpendicular to Z-axis are set to X (X-axis) direction and Y (Y-axis) direction, and a direction of the photographed object is set to forward direction of the optical axis direction (+Z side).
As shown in FIG. 7(b), the lens driver 30 with camera shake reducing function is composed of an auto-focusing unit 31 and a camera shake reducing unit 32. The auto-focusing unit 31 comprises: a lens holder 34 that holds the lens 33; a coil for focusing 35; a magnet for focusing 36; a magnet holder 37; a front spring member 38A; and a back spring member 38B.
The camera shake reducing unit 32 comprises a base carrier 39, a suspension wire 40, a magnet for focusing 36 that is shared with the auto-focusing unit 31, an X-side wire for swinging 41X and a Y-side wire for swinging 41Y.
On the inner circumference of the magnet for focusing 36 of the auto-focusing unit 31, the coil for focusing 35 is winded along Z-direction and mounted on the outer circumference of the lens holder 34. The magnets for focusing 36 are plate-shaped, and cause the magnet pole to face the coil for focusing 15, and they are arranged at an interval of 90 degree around an axis parallel to Z-axis. The coil for focusing 35 faces the magnet for focusing 36 with a gap between them, and the magnet for focusing 36 is held at the magnet holder 37. The +Z side of the magnet holder 37 is connected with the front spring member 38A, and the −Z side of the magnet holder 37 (a direction opposite to the photographed object side) is connected with the back spring member 38B.
On four corners at +Z side of the magnet holder 37, the front (+Z side) ends of four suspension wires 40 that extend along Z direction are connected, and on four corners at +Z side of the base carrier 39 of the camera shake reducing unit 32, the back (−Z side) ends of the suspension wires 40 are connected. The magnet holder 37 is supported by the suspension wire 40 in form of a suspension rack such that it may swing along X-direction and Y-direction.
The base carrier 39 is a plate-like member that is opened in the center and oriented in Z-direction. On a surface on +Z side of the base carrier 39, a coil for swinging 41X at X side and a coil for swinging 41Y at Y side are mounted that are winded along Z-direction and which are track-shaped. Two coils for swinging 41X at X side and two coils for swinging 41Y at Y side are arranged around an opening that is placed in the center of the base carrier 39, and face the lateral side of the magnet for focusing 36 on −Z side with a gap between them in Z-direction.
The coil for focusing 35 of the auto-focusing unit 31 generates a Lorentz force in Z-direction as the coil for focusing 35 is energized, so that the lens 33 moves forwards in Z-direction or backwards in Z-direction.
The coils for swinging 41X at X side generate a Lorentz force in X-direction as the coils for swinging 41X on X side of the camera shake reducing unit 32 are electrified, and thus a reaction force will be applied to two magnets for focusing 36 that face the coils for swinging 41 X at X side, so that the auto-focusing unit 31 swings in X-direction. Furthermore, the coils for swinging 41Y at Y side generate a Lorentz force in Y-direction as the coils for swinging 41Y on Y side are electrified, and thus a reaction force will be applied to two magnets for focusing 36 that face the coils for swinging 41Y at Y side, so that the auto-focusing unit 31 swings in Y-direction.
Patent document 1: Japanese patent publication No. JP 2013-24938.
After the lens driver 30 with camera shake reducing function has been completely assembled, the lens 33 is mounted in a manner that it engages with the lens holder 34 of the lens driver 30 with camera shake reducing function. That is, on the inner circumference of the lens holder 34, a part is processed in form of a thread or an engaging protrusion, and the lens 33 is inserted from +Z side, and mounted due to a force applied by screwing and hooking, etc. However, when the lens 33 is mounted onto the lens holder 34, it is sometimes pressed in −Z direction into a position in which the auto-focusing unit 31 collides with the camera shake reducing unit 32. As a result, the suspension wire 40 may sometimes undergo a bending accompanied by a plastic deformation (plastic bending). When an impact force caused by falling-down is applied to the lens driver 30 with camera shake reducing unit, the auto-focusing unit 31 is sometimes pressed by this impact force in −Z-direction into a position in which it collides with the camera shake reducing unit 32, and the suspension wire 40 may undergo a plastic bending. if the suspension wire 40 has a plastic bending, then the auto-focusing unit 31 may be dislocated, or tilted relative to the camera shake reducing unit 32, and the possibility increases that it causes a poor operation of the camera shake reducing function. Furthermore, the possibility increases that a tilted auto-focusing unit 31 of the suspension rack leads to a deformation of the photographed image.